The analysis of the aromatic composition of the traditional watermelon soybean paste were studied by HS-SPME com-bined with GC-MS. Results showed that there were 63 flavor including alcohols,esters,acids,aldehydes, phenols, ketons, Furan class and ethers in the traditional watermelon soybean paste.Besides, the relative content of flavoring compositions was determ ined by peak area.The main volatile flavor components identified in the relatively higher peak area percentage (＞2% )were acetic acid（26.478%），1-butanol,3-methyl-（15.800%），n-butyl formate (7.233%)，ethanol(3.739%)，2-butanol(3.516%)，(dl-Limonene)Dipentene（2.950%），beta.-Thujene（2.207%），Ethyl Acetate（2.490%），Sabinene（2.159%），Butanal, 2-methyl-（1.192%）which plays an important role in the flavor of traditional watermelon soybean paste 。